Cutter mechanism for turning lasts or the like



1944' A. D. LANDERS ET AL 2,354,689 0 I CUTTER MECHANISM FOR TURNING LASTS OR THE LIKE Filed Dec. 29, 1941 4 Sheets-Sheet 1' Fig.1.

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9 1944- A. D. LANDERS ET AL 2,354,689

CUTTER MECHANISM FOR TURNING LASTS OR THE LIKE Filed Dec. 29, 1941 4 Sheets-Sheet 2 Aug 1944- A. D. LANDERS ETAL 89 CUTTER MECHANISM FOR TURNING LASTS OR THE LIKE 4 Sheets-Sheet 4 Patented Aug. 1, 1944 CUTTER MECHANISM Fort. TURNING LASTS on THE LIKE Alton Landers and .Fred Lindsay, Brockton, Mass, assi nors to. Woo ard & Wright Last 00.. East Bridgewater, Mass, a'fcorporation of 'Masaehusetts Application December 2 9, 1941-, Serial ,No. 424,74

' .Our present invention relates to improvements in last turning or like lathes and has for its objects improvement of the speed and accuracy of t r in opereti nsand c eased efl enev and economy inftlie operation-and maintenance of such lathes; I

In the development'of these 'lathes. there long has been indieated he advanta e o sm ll diameter cutt'ers,"but their use has heretofore involved such various difficulties and conflicts of possible remedial factors that their adoptiohjhas been re tarded. I

' Noticeable difliculties with la'thes prior to our invention were inaccurate and rough cutting, vioration, the de opment of excessive heat, t e ne e sity forifrequent sha peni and replacementjof the cutting elements, and for other serve '1 I of iathesyin accordance with our invention, we

ice. These diflicultiesallcontribute to limit the productive capacity @oft lathe the quality of the products turne 1111661111 These general object s a be mgre'readn'y appreciated by ananalysis of certain elements of: lathe now common y used and oith se' e e ment s ,the cutting meansmerit special consideration. e

The cutting means :of commercially used ,last turning lathes consisted of finishing .cutters and roughing cutters, the latter being in effect rotary ehisels employed to h pe the-b o k, t e t ned t pe mi finishin y e emova h e t el thin e ips hvthehn s ine cut ers- We prov deaeuttine mea s in wh ch a series o p sha ed cu ers are i ized a d nce ehoundcuttine ed es eteinthe r-sha phe s e ser whenemployed-to remove substantial amounts or stock. we so space the utters relative to each other and to theaxisof rotation of i heirsuppoh ing shaft that cutters are available to rough the block to a shape insuring that the principal roughing cutter {and .the finishing .cutter each have a constant andsubstantial amount of stock toremove. v

order to provide .-a simple and rugged sup port tor .the cutters and to insure the dissipation of heat developed by-jhighspeed lathe operations, we provide ,a'unitary cutter head and drive shaft supported in bearingswith itsdriveipulley .on its end. This construction not only insurescoolop eration, but also makes belt replacement: ex.- trem ly easy. 'Iihe remarkable .efiiciency of this ,construction'iis evidenced by greatly increased placement.

have provided the carriage supporting the cutting meanswwith a motor mount centering its weight and the weight of the unitary cutter shaft and. head so that vibration is eliminated as the carriage traverses its supporting bed.

.lSuch and other advantages will more fully appear in the discussion of the improvements hereinin-volved and illustrated in a lathe of generally standard type to such extent as seems necessary as a basis for the description ofand claims for the present invention, but not-atall as to their limitation, as other machines are in use that may be substantially improved by additions to or substitutions for ineflicient parts of their present combinations.

'Inthe drawings "Fig. l is a front elevation-of a lathe according to our invention.

"Fig. ;2 shows the lathe of Fig. 1 in end View.

' Fig.3;is a plan view of the same with'certain parts omitted for clarity in illustration.

7 Fig. 4 is a fragmentary side view showing the unitary cutter head and drive spindle. Fig. 5 'isfa partly sectioned end View of the a I Fig.1) is a schematic development showing the relation of the cutting elements to each other.

7 shows, in directside elevation, the cutting means, the drive therefor and the supporting carriage.

' Fig.8 is a development of the relations of meansto support and rotate a model and the block to be' turned, a unit comprising a model wheel and the cutting head and its .drive, and a drive to feed the unit so that the model wheel and the euttingh ad tr ver ther a smode and t r tat g block. the su or n means fo :Whieher t ee to swi s ;that th action o the cutting means :follOWS the contours of the model. v.

The latheconsists of a .bed I .and an overhead frame .2 supported on legs 3. The overhead frame Z-Apivdtally supports the-swing frame 4 as at 5. Conventional rotatable model supports, are indicated at 6 and l and similar rotatable supports At its outer end the portion 41 is milled to form pairs of webs 48, 49 and 50 and The faces 48a. and 49a. of the webs 48 and 49 are in radial alinement with respect to the axis of the 5 shaft 44 and at right angles to the radially alined faces 50a and 5la of the webs 50 and 5|. Each of. the :webs is formed with a radially :enlarged portion 52 drilled tor-permit .:;the detachable mounting of cup-shaped cutters. As the cutters S: id. 7 are identical, I have indicated them generally as turned, held by the supports 8 and 9, are positives; ly rotated.

The model wheel 22 to contact the model and control the position of the swing frame 4 is con ventionally adjustably mounted on a carriage;

' rotated whenftheoperative portions of their cut- 23 slidably supported on parallel ways 24 on the bed I. A carriage '25 slidablysupported on the motor, later to be described.

The carriage 25 is driven by the motor 26 which has a belted connection-21 with the shaft 28 having a worm gear 29 in mesh with the gear. wheel 30 the-shaft 3| of which is journaled in the bed I and carries a gear 32 in mesh with the rack portion 33 ofthe carriage 25. v

The carriages 23 and 25 are interconnected by the adjustable linkage 34 one end of which is pivotally attached to the carriage 25 and the other end of which is adjustably pivoted to the lever 35 adjustably fulcrumed as at 36. Thiseis conventional fgrading mechanism whereby equal, greater, or less movement of thecarriage 23 resultsupon movement of the carriage 25. As

grading operationsare conventional we have not described them in detail or the mechanism by which they are efiectedl From the foregoing it will be apparent that the model wheel 22 and the cutting mechanism move as a unit on the bed I with the model wheel 22 in contact with the rotating-model. The swing frame 4 is actuated by such contact ,to move the work to be turned nearer to or farther away from the cutting mechanism to shape the block according to the model. i

In order to control the swinging of the frame 4, it has been the practice to provide a weight to insure the constant contact of the model with the model wheel 22. In prior lathes, such weights were so mounted that their influence was not con-. stant. We connect the frame 4 to a crank'ii! by av link 38 and mount on the crank shaft '3'laa pair of collars 39 to which the weight 40 is co centrically pivoted so that its influence on the frame 4 is constant as the frame 4 swings towards or away from the vertical. I I The lathe as thus far described is conventional except for motor drive for the carriages, the mo tordrive for the model'and the block to be turned, and for the counterweighting of the swing frame 4. We have omitted from the drawings many de-" tails of construction to simplify the drawingsas these are not essential to a proper understand: ing of the construction and operation of lathes in accordance with our invention.

We'provide the 'carriage25 with a mount 4f consisting of a pair of spaced standards 42 set diagonally of the lathe ways 24. The standards 42 include anti-friction bearings, as for example roller bearings 43 in support of the shaft 44. 1

The rearwardly disposed portion of the shaft 44 extends'beyond the carriage 25 and supports a pulley 45 and a flywheel 4B and its forwardly disposed portion. is reduced as at 41 to insure theaccommodation of work to be turned withoutcontacttherewith. r

at C in,certai n views. The cutters C are supported'and'held against rotation by bolts 53 car- "i'yi'ng' nuts 54 by which the cutters C may be {tightly.seatedagainst the radially disposed web f-aces orloosened to permit them to be partially ting edge become worn, thereby bringing into an lathe ways 24 carries the cutting meansand-dt's operativei position-"asharp portion thereof To hold the bolts 53 against rotation, we form them andthe holes through which they extend slightly oval. The rear faceof each Webis milled out ssess, 'toiaccommodate a portion of the cutter C "carried' by' 'the{a djacent web, l

s S110;W Il.;ln.Fl g.. '9, the axis A ofthe'shaft 44 5 is disposed at mangle, f rablyior 30, to. the axis of the work to be'turn'e'd defined by the supports 8 and 9 andindicated at BinFig. 9.,

' While each of the cuttersfCj is" identical, their function is individual and hence we have in'Figs, l," ac, and sf c ntin d theffcur cutters em" pio' egat 6, ,5 1 i f 1 f' I; The cutter'56 'is' the finishing cutter and as may be most clearly seen in Figs. 6 and 8, it "is disposed a maximum distanc'efrom the axis A. 5 The cutter 5 is placed inwardly longitudinally and radially of the cutter 56 to provide a definite butjsubstantial amount of work'for the cutter-"56; While the cutter 5 !is.t he roughing cutter, we employ the cuttersj 58fandf59' to insure that the amount of work requiredofthecutterfl is con stant. The cutters 58-and 58 {are spaced radially inwardly of-the cutter 51 an equal distance but arespaced axially therefroim and from each other to 'ihsu'r'e cooperative rough shaping of the wood so that the work *o'f'the cutter" 51 'is constant. As shown in Fig. 9, the line of the cutting edges may be' 'considered' asfdefining "an angle of 43 T .1 j fweirerer 'totl'i'eportion 41 of the'shaft 44 and th'e'cutters mounted thereon as thecutting'hea'd and -in-accordance with our invention, the head is perfectly balancedk "For example, if one of the cuttersisregro'und we 'restore'the desired balance by adding a shim between-the cutter and the face of its-supporting w'eb.- Such shim or shims are' of coursethinand accordingly'we have only indicated ats in-=Fig. 5 the location-thereof when necessary to insure 'the balance-of the cutting head:

The shaft 44 is rotated by'the motor so through the belt s1- interconnecting -th'e motor pulley .62

and'the pulley'45. In accordance with our inven-,. tion, we insure smooth and accurate las'tturning by soi mounting the motor-60 that the carriage 25 :r'est's evenly on the lathe wayss24- at all times;

.i. W accomplish thisiresult by providing the-carriage -25 iwith ai= hanger =63 depending fromthe carriage: 25 jinWitSfiCe ntraJ zone; The base'oi the motor-ow is bolted; to a plate 6.4..the. rear. part .of

7 which isipivotally connected as at 65 to the hanger 63. We form the front part ofthe plate 64 with apair ofv ea'rs...66 for aipinzSl passing througha bearing 8 having a threaded-stem69 extending through the bracket 70; on the hanger 63- and ad 7m justably locked in position by nuts 1L; -By. this construction, the weight of the motor 60 is centered and the position of the motor 60 may be easily adjusted to place the belt 6| under proper tension. It will also b appreciated that because the pulley 45 is on the end of the shaft 44 so that the belt 6| is externally of the carriage 25, it may be quickly and easily replaced.

Our invention has the further advantage of insuring cool operation. As the shaft 44 is of substantial diameter and the support for the cutters is integral therewith, heat is rapidly conducted away from the cutting head. Th efiectiveness of our combination in dissipating heat is particularly noticeable by the coolness of the belt GI and its attendant long life.

As we have explained, the disposition of the cutters on the forwardly disposed part of the shaft 44 not only provides a rugged cutter head and eliminates the expensive roughing cutters formerly employed, but also provides for greater accuracy and effectiveness in operation and increased cutter service at a minimum expense. With lathes embodying our invention, the time required to turn lasts may b reduced from eight or nine minutes to three or four minutes, and if desired, a last can be turned from an unslabbed block thus saving the expensive and dangerous rough shaping of the block in accordance with usual practice. The production capacity of lathes in accordance with our invention is further inciency and economy of lathes in accordance with our invention. What we therefore claim and desire to secure by Letters Patent is:

1. Cutting mechanism for turning irregular objects, said mechanism comprising a rotatable cutter supporting member having an end formed with a plurality of webs, at least one set of corresponding faces of which are equi-angularly spaced, each of said webs including a radially enlarged portion and'the other set of corresponding web surfaces being recessed to an extent sufiicient to define with an adjacent enlarged portion a seat, one of said creased by the fact that the cutters remain sharp seats being disposed adjacent the end of said membera predetermined distance from its axis, and the other seats being successively disposed radially and axially inwardly of said first seat and from each other, and a cup-shaped cutter anchored against each of said seats.

2. The mechanism of claim 1 in which the first-named set of web surfaces are radially disposed.

3. The mechanism of claim 1 in which there are four webs and the first-named set of web surfaces are radially disposed and the other set of web surfaces are disposed at right angles thereto.

4. Cutting mechanism for turning irregular objects, comprising a. rotatable cutter-supporting I member having an end formed with a plurality of webs extending radially of the cutter axis, at least with said flat surface a seat, and a cup-shaped cutter anchored in said seat.

ALTON D. LANDERS. FRED H. LINDSAY. 

